High acrylonitrile polymer solutions containing a mixture of monochlorinated orthophenylphenols



United States Patent 3,284,395 HIGH ACRYLONITRHLE POLYMER SOLUTIONS (IQNTAINTNG A MIXTURE 0F MONOCHLORI- NATED ORTHUPHENYLPHENOLS Fred J. Lowes, .lia, Midland, Mich, assignor to The Dow Chemical Company, Midland, Mich, a corporation of Delaware No Drawing. Filed July 26, 1965, Ser. No. 474,945 13 Claims. (Cl. 260-296) This application is a continuation-in-part of copending application Serial No. 177,216, filed March 5, 1962, now abandoned. I

This invention relates to compositions of matter that are especially adapted for use in spinning acrylonitrile polymer synthetic textile fibers or the like structures having long-lasting bacteriostatic properties. It relates more particularly to spinnable solutions of such polymers in concentrated aqueous salt solutions having minor but effective amounts of a bacteriostatic agent composed of a mixture of 6-chloro-2-phenylphenol and 4-chloro-2- phenylphenol dissolved therein. The invention is also concerned with shaped articles especially filamentary structures, having bacteriostatic properties, and to a process for preparing such compositions, and articles.

The word solution is used herein in the connotation commonly employed in the acrylonitrile polymer spinning art.

Polyacrylonitrile and many of the fiber and film-forming copolymers of acrylonitrile may advantageously be fabricated by a wet spinning process wherein the polymer composition is extruded from compositions of the polymer in polyacrylonitrile-dissolving aqueous saline solvents, particularly aqueous solutions of zinc chloride and its saline equivalents. Such a procedure, as is Well known in the art, is oftentimes referred to as salt-spinning with the fibers (or other shaped articles) obtained thereby being salt-spun. In salt-spinning, the fiber-forming, aqueous saline spinning solution or other composition of the polymer is extruded during the spinning operation into a non-polymer-dissolving coagulation liquid, or spin bath, which frequently is a solution of the same salt or salts as are in the spinning solution.

Acrylonitrile polymers (including fiber-forming copolymers), particularly polyacrylonitrile, that are salt-spun in the referred-to manner are generally formed as aquagel intermediates. Such intermediates have a water-swollen or hydrated structure prior to their being finally irreversibly dried to the desired, characteristically hydrophobic, product.

Advantageously, the aquegel structures of polyacrylonitrile and other fiber and film-forrning acrylonitrile polymers may be derived by the extrusion of a solution of the acrylonitrile polymer that is dissolved in an aqueous zinc chloride saline solvent therefore into an coagulation in an aqueous coagulating spin bath. It is usually desirable for zinc chloride to be at least the principal (if not the entire) saline solute in the aqueous saline solvent solution.

If preferred, however, various of the saline equivalents for zinc chloride may also be employed in the aqueous saline solvent medium for the spinning solution and the coagulating bath utilized. These zinc chloride equivalents, as is well known, include various of the thiocyanates (such as calcium thiocyanate) lithium bromide and the salts and salt mixtures that are solvent members of the so-called lyotropic series as are disclosed, among other places, in U.S. 2,140,921; 2,425,192; 2,648,592; 2,648,593; 2,648,646; 2,648,648; and 2,648,649.

Fibers produced from acryonitrile polymers have excellent physical properties but do not have the inherent ability to inhibit the growth of bacteria. The textile industry is particularly interested in a fibrous material useful for the production of blankets, carpeting and the like, which has the desirable properties of polyacrylonitrile or fiber-forming copolymers containing at least 85 weight percent of acrylonitrile in the polymer molecule and in addition has the ability to inhibit the growth of bacteria and to destroy existing bacteria. It is also highly desirable to prepare heat-shrinkable, flexible films useful for bottle closures and the like applications which have longlasting bacteriostatic properties.

Fabricated acrylonitrile polymer film, textile fibers and like filamentous articles derived from saltspinning processes are generically described as being capable of lying substantially in a single plane, having at least one major dimension, and at least one minor dimension less than about 0.1 inch, said articles being characterized by having orientation of the molecules parallel to one another and to a major axis of the article.

The foregoing statement of the problem has referred to fibers and films, and the invention will be illustrated with respect to fibers. The problem is more general, however, and applies to the defined compositions in the forms of sheets, tubes, rods and molded articles as well as films, fibers and other filaments.

It is the primary object of the present invention to provide compositions of matter especially adapted for use in spinning synthetic films and textile fibers or like structures of high acrylonitrile polymers (i.e. those having at least 85 weight percent of polymerized acrylonitrile in the polymer molecule) having long-lasting bacteriostatic properties.

A further object is to provide shaped articles from the compositions of the present invention which have longlasting bacteriostatic properties.

A still further object is to provide a process of producing the compositions and articles of the present invention.

Other and related objects will become evident from the following specification and claims.

In accordance with the present invention high acrylonitrile films and textile fibers having long-lasting bacteriostatic properties are produced from. a polymeric spinning solution comprising (1) an acrylontrile polymer containing in the polymer molecule at least about 85 weight percent of acrylonitrile, said polymer dissolved in an aqueous saline solvent solution, preferably where zinc chloride is the principal (if not entire) saline solute, and (2) dissolved therein at least about 5 weight percent, based on said fiber-forming polymer weight of a bacteriostatic agent composed of a mixture of 6-chloro-2-phenylphenol and 4-chloro-2-phenylphenol as described herein.

The acrylonitrile polymer employed in practice of the present invention is, advantageously, polyacrylonitrile, although, as is readily apparent, any of the well known fiber and film-forming copolymers thereof that contain, polymerized in the polymer molecule, at least 85 weight percent of acrylonitrile with at least one other ethylenically unsaturated monomer that is copolymerizable with acrylonitrile, may, beneficially, be utilized. The acrylonitrile polymer employed is, of course, soluble in an aqueous saline solvent for acrylonitrile which, usually, has therein at least about 50-60 weight percent of zinc chloride or its saline equivalents, US. 2,776,946, among many other reference sources, exemplifies many of the monomers which may be copolymerized or interpolymerized with acrylonitrile to produce binary or ternary acrylonitrile copolymers that are useful in the practice of the invention.

The bacteriostatic agent which is useful for the purpose of the present invention as commonly prepared is composed of predominent amounts, usually about weight percent, of 6-chloro-2-phenylphenol with the re- Other ratios of separately placed in individual glass bottles. Thereafter, to one of the solutions was added, with stirring, 10 weight percent of an isomeric mixture composed of about 80 weight percent 6-chloro-2-phenylphenol and about 20 to those skilled in the art. weight percent of 4-chloro-2-phenylphenol. To another The above defined bacteriostatic agent which is suitable solution, for purpose of comparison, was added, with stirfor the present invention is compatible with the acryloniring, 10 weight percent of 2,4,5-trichlorophenol, and to yet trile polymers defined herein when incorporated in said another solution was added 10 weight percent of o-phenylpolymers by the process of the present invention. phenol. Each of the samples was then placed in a stand- It has also been found that the bacteriostatic agent here- 10 ard laboratory oven maintained at a temperature of about in described must be present in the polymer solution in a 80 C. until each of such samples was free from bubbles. minimum amount of about 5 weight percent based on the Each of the bubble-free spinning solutions was then inweight of the acrylonitrile polymer if the objectives of dividually extruded through a spinnerette having about the invention are to be attained. The permissible maxi- 300 orifices (each orifice having a diameter of about 3 mum proportion depends on the limit of its compatibility mils), into an aqueous non-polymer-dissolving zinc chlowith the aqueous saline solution, as well as the polymeric ride coagulating bath. The aquagels individually formed material contained therein. The maximum limit is genertherein were separately spun into a multiple filament ally about weight percent, based on the weight of the aquagel tow and collected, and the resulting aquagel tows acrylonitrile polymer. water washed until substantially free of zinc chloride.

The amount of bacteriostatic agent present in shaped 20 There were thereby separately obtained individual aquaarticles produced from salt-spun acrylonitrile polymers is gel filament tows containing about 1 part water for each dependent upon, and approximately in the same ratio as, part of polymer therein. The aquagel filament tows were the amounts of said bacteriostatic agent incorporated in h n each separately oriented by being stretched to a the spinning solution. length of about 10 to 12 times their original extruded The bacteriostatic agent of the present invention may gth and allowed to air dry at normal room temperabe suitably admixed with the polymeric spinning solution tllreS- by stirring at room temperature. The filament tows were then finally irreversibly dried It has been found that the bacteriostatic agent useful for 0 t5 inut s at about 1 0 C. for the instant invention is compatible with the acryloh ried filament tow was them individually placed nitrile polymers d fi ed her i h n u ed i th pre- 3 on the surface of a nutrient agar contained in a convenscribed amounts, and, is substantially water-insoluble. tiehelly-hsed Petri dish P Which agar had been The above combination of desirable properties prevents Previously inoculated With Staphylococcus alllclls y excessive extraction of the bacteriostatic agent from the smearing the Surface of the nutrient agar With Swab polymer during coagulation of the polymer solution in an from a broth culture of Staphylcccccus The aqueous non-polymer-dissolving li di d d dishes were then set aside for incubation at a temperature ing subsequent wat r washing f th lti aquagel between about 30 C. and 37 C. After incubation, the d shaped a ti l od d th f plates were examined to determine the extent of control of Shaped articles produced from acrylonitrile polymers by the growth of the organisms of Staphlcccccllc allrcllsthe process of the present invention do not significantly EXamiIlation 0f the Plates Supporting the filament teWS lose their bacteriostatic properties even after repeated 40 containing the mixture 0f6-eh10r0-2-Phehy1Pheh01and laundering, chloro-2-phenyl henol showed a zone of about 1 mm. It will be appreciately by those skilled in the art that immediately Surrounding Said tOWS ich was free of various other materials can be added to the compositions the growth of the organisms of Staphylococcus dwellsof the present invention. Such materials include, for ex- Examination of a Series of PlateS Supporting individual ample, plasticizers, lubricants, dye assistants, dyes and pigfilament tows containing the following known bactericments. static agents: 2,4,5-trichlorophenol and o-phenylphenol The following example, wherein all parts and per ent Showed that in all instances, a heavy outgrowth of colonies ages are to be taken by weight, illustrates the present inof Staphylococcus Wells Was Present in the Zone immevention but is not to be construed as limiting its scope. diately Surrounding Said tOWS- EXAMPLE 1 The unexpected effectiveness of the bacterio static agent of the present invention, when utllized 1n COmbIH'HtIOIl with In each of a series of experiments, separate charges of a fiber and film forming acrylonitrile polymer as herein about 35 grams of a solution consisting of 10 percent described, is illustrated by the following tests wherein polyacrylonitrile, 54 percent zinc chloride, and 36 percent the bacteriostatic properties of each of the above referred water, all based on the total weight of the solution, were 55 to compounds were individually determined. In such Table I Baeteriostatic Agent A ar 11 Organlsm Tested Type Concit islloaviiiig i ri til i itfi ii p.p.m.

Sta M10 0 p 1 gi'fn cnomphenn 10 53233; 83355813 2,4,5-Tr1chlorophenol 50 Essentially free of growth. Mixture of (i-chloro and 4-ehl0ro-2- 10 Heavily overgrown.

phenylphenols. lllglggrrlglgegcllsiloro and 4-chloro-2-' 50 Essentially free of growth. salmoncllatyphgsa OPhenylphenol 50 lly free of growth Aerobacter aerogenes.

None 2,4,5-Trichlorophenol Heavily overgrown.

50 Essentially tree of growth M1xture of fi-chloro and 4-chloro-2- 50 H Mpwenylplflenolsi eavlly overgrown.

1x ure 0 6-011 ore and 4-chloro-2- phenylphenols. Essentially free of growth. gPhenylphenol 100 Essentially tree of growth.

one Heavily overgrown. 2,4,5-Tr1c11l0rophenol 50 Essentially free of growth. Mixture of 6-chloro and 4-ehlor0-2- 50 Heavily overgrown.

phenylphenols.

tests, the materials evaluated were individually dispersed in nutrient agar to prepare individual Petri dishes of agar medium containing from about to 100 .parts per million by weight of one of said compounds. The surfaces of these dishes were inoculated with one of several organisms as hereinafter identified by smearing the surfaces with a swab from a broth culture of such organism. At the same time, Petri dishes containing untreated agar media were similarly inoculated from the same broth culture, the dishes were set aside for incubation at a temperature of 30 C., for 72 hours. After incubation, the plates were examined to determine the control of the growth of the organism. Examination of the treated plates provided the data appearing in the above Table I.

It will be seen by reference to the data of Table I that the comparative materials, as specifically identified therein, are generally at least as effective as bacteriostats per se as the bacteriostatic agent employed for the purposes of the present invention.

Similar good results as specifically set forth herein are obtained by utilization of from about 5 to 20 weight percent of polymer weight of a bacteriostatic agent composed of a mixture of 6-chloro-2-phenylphenol and 4-chlo no-2 phenylphenol, as contemplated by the present invention.

In addition, similar good results are obtained when fiber and filmaforming acrylonitrile polymers containing at least 85 weight percent of polymerized acrylonitrile and up to weight percent of one or more of such eo-polymerizable materials as vinyl chloride, vinyl acetate, methyl and other alkyl acrylates or methacrylates, the vinyl pyridines, allyl alcohol and many others well known to those skilled in the art are admixed with the prescribed amounts of the bacteriostatic agent of the present invention.

What is claimed is:

1. Bacteriostatic composition comprising a spinnable solution of: (1) a fiber-forming acrylonitrile polymer which contains in the polymer molecule at least about 85 weight percent of acrylonitrile, any balance being another monoethylenically unsaturated monomeric material that is copolymerizable with acrylonitrile, (2) an aqueous saline solvent for polyacrylonitrile; said solvent having additionally dissolved therein (3) at least about 5 weight percent based on said fiber-forming polymer weight of a bacteriostatic agent composed of predominant amounts of 6 chloro-2-phenylphenol with the remainder being 4- chloro-2-phenylphenol.

2. The composition of claim 1, wlierein the bacteriostatic agent is composed of about 80 weight percent of 6-chloro-2-phenylphenol and about Weight percent 4- chloro-Z-phenylphenol.

3. The composition of claim 1, wherein the bacteriostatic agent is present in amounts between about 5 and 20 Weight percent based on the weight of said fiber-forming polymer.

4. The composition of claim 1, wherein said fiber-forming polymer is polyacrylonitrile.

5. The composition of claim 1, wherein said aqueous saline solvent is a solution of zinc chloride.

6. In the process of producing bacteriostatic articles from a spinning solution of a fiber-forming acrylonitrile polymer which contains in the polymer molecule at least about 85 weight percent of acrylonitrile, any balance being another monoethylenically unsaturated monomeric material that is copolymerizable with acrylon-itrile, which polymer is dissolved as a spinnable composition in an aqueous saline solvent for said fiber-forming polymer; the step of dissolving in said spinning solution at least about 5 weight percent, based on the weight of said fiberforming polymer in said spinning solution, of a bacteriostatic agent composed of predominant amounts of 6chloro-2-phenylphenol with the remainder being 4-ohloro-2- phenylp-henol.

7. The process of claim 6, wherein the bacteriostatic agent is composed of about weight percent of 6-chloro- Lphenylphenol and about 20 weight percent of 4-chloro- Z-pheny-lphenol.

8. The process of claim 6, wherein the bacteriostatic agent is present in amounts between about 5 and 20 weight percent based on the Weight of said fiber-forming polymer.

9. The process of claim 6, wherein said fiber-forming polymer is polyacrylonitrile.

10. The process of claim 6, wherein said aqueous saline solvent is a solution of zinc chloride.

11. A polymeric filament having bacteriostatic properties comprised of (l) a fiber-forming acrylonitrile polymer which contains in the polymer molecule at least about weight percent of acrylonitrile, any balance being another monoe-thylenically unsaturated monomeric material that is copolymerizable with acrylonitrile, (2) dispersed throughout at least about 5 weight percent based on said fiber-forming polymer weight of a bacteriostatic agent composed of predominant amounts of 6-chloro-2-phenylphenol with the remainder being 4-chloro-2-phenylphenol.

12. The filament of claim 11, wherein the bacteriostatic agent is composed of about 80 weight percent of 6-chloro-2-phenylphenol and about 20 weight percent of 4-chloro-2-phenylphenol.

13. The filament of claim 11, wherein the bacteriostatic agent is present in amounts between about 5 and 20 weight percent based on the weight of said fiber-fonming polymer.

References Cited by the Examiner UNITED STATES PATENTS 1,969,963 8/1934 Britton et al. 260620 2,460,377 2/1949 Capiro 106-486 2,533,224 12/1950 Cresswell 260-29.6 2,763,636 9/1956 Davis 26029.6 2,873,263 2/1959 Lal 260-85.5

MURRAY TILLMAN, Primary Examiner.

N. OBLON, Assistant Examiner. 

1. BACTERIOSTATIC COMPOSITION COMPRISING A SPINNABLE SOLUTION OF: (1) A FIBER-FORMING ACRYLONITRILE POLYMER WHICH CONTAINS IN THE POLYMER MOLECULE AT LEAST ABOUT 85 WEIGHT PERCENT OF ACRYLONITRILE, ANY BALANCE BEING ANOTHER MONOETHYLENICALLY UNSATURATED MONOMERIC MATERIAL THAT IS COPOLYMERIZABLE WITH ACRYLONITRILE, (2) AN AQUEOUS SALINE SOLVENT FOR POLYACRYLONITRILE; SAID SOLVENT HAVING ADDITIONALLY DISSOLVED THEREIN (3) AT LEAST ABOUT 5 WEIGHT PERCENT BASED ON SAID FIBER-FORMING POLYMER WEIGHT OF A BACTERIOSTATIC AGENT COMPOSED OF PREDOMINANT AMOUNTS OF 6-CHLORO-2-PHENYLPHENOL WITH THE REMAINDER BEING 4CHLORO-2-PHENYLPHENOL. 